JP2018124610A - Image processing apparatus, printing system, and image processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology of quickly starting printing.SOLUTION: An image processing apparatus includes: an arrangement determination unit which determines arrangement of images; a rendering execution unit which executes rendering on the images, according to a result of detection processing that detects off-line, in a range including the images arranged based on a determination of the arrangement determination unit, where no image exists through the range in a second direction orthogonal to a first direction in which a printing medium is conveyed; and a halftone execution unit which executes halftone processing on the rendered images to be output to a printer. The rendering execution unit executes rendering on a first image of the images located downstream of the off-line in the first direction and executes rendering on a second image located upstream of the off-line in the first direction. The halftone execution unit executes halftone processing on the rendered first image in parallel with rendering on the second image by the rendering execution unit.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an image processing technique for performing rendering and halftone processing on an image.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique for suppressing the start of printing from being delayed due to the time required to develop print data into page data. Specifically, the printer controller described in Patent Document 1 divides a print job at page breaks, divides the print job into a plurality of divided jobs, and transfers the divided jobs to the printing apparatus for each divided job.

JP 2002-091748 A

  However, since the above technique divides a print job at page breaks, its application range is limited. As a specific example, when printing a plurality of images arranged by nesting on a roll-shaped print medium, the above technique cannot be adopted because there is no concept of pages. Therefore, there is a case where another technique that can realize a quick start of printing without using the concept of a page is required.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique capable of promptly starting printing.

  An image processing apparatus according to the present invention includes a layout determination unit that determines a layout of a plurality of images, and a print medium that is transported by the printing device in a target range that includes a plurality of images that are arranged based on the determination of the layout determination unit. A rendering execution unit that performs rendering on a plurality of images according to a result of detection processing that detects an offline state in which an image does not exist through a target range in a second direction orthogonal to the first direction, and rendering is performed by the rendering execution unit A halftone processing unit that performs a halftone process on the processed image and outputs the image on which the halftone process has been performed to a printing apparatus, and the rendering execution unit includes a plurality of images in a first direction from the offline. Rendering the first image downstream and then rendering the second image upstream in the first direction from the offline, Line unit, in parallel with the rendering of the second image by the rendering execution unit, executes a halftone process rendering by the rendering execution unit to execute previously first image.

  A printing system according to the present invention includes an image processing device, and a printing device that prints a plurality of images output from the image processing device while conveying the printing medium in a first direction. Of the target range including a plurality of images arranged based on the determination of the layout determination unit and the layout determination unit that determines the layout of the plurality of images, no image exists through the target range in the second direction orthogonal to the first direction. In accordance with the result of the detection process for detecting offline, a rendering execution unit that performs rendering on a plurality of images, and halftone processing is performed on the image that has been rendered by the rendering execution unit. A halftone execution unit that outputs an image to a printing apparatus, and the rendering execution unit includes a first one of the plurality of images on the downstream side in the first direction from the offline. After rendering the image, rendering is performed on the second image upstream in the first direction from the offline, and the halftone execution unit performs rendering by the rendering execution unit in parallel with the rendering of the second image by the rendering execution unit. The halftone process is executed on the first image that has been executed.

  An image processing method according to the present invention includes a step of determining an arrangement of a plurality of images, and a target range including the plurality of images arranged based on the determination, orthogonal to a first direction in which a printing medium is conveyed by a printing apparatus. A step of performing rendering on a plurality of images according to a result of detection processing for detecting an offline state where no image exists in the second direction through the target range, and a step of performing halftone processing on the rendered image And outputting a halftone-processed image to a printing apparatus, and in the rendering step, rendering is performed on a first image downstream of the plurality of images in the first direction in the first direction. In the process of rendering the second image upstream from the offline in the first direction and executing the halftone process, the second image is rendered in parallel. Te, it executes a halftone process rendering the already executed the first image.

  In the present invention (image processing apparatus, printing system, and image processing method) configured as described above, an offline where no image exists in the second direction orthogonal to the first direction in which the printing medium is conveyed by the printing apparatus is detected. . Then, the plurality of images are divided into a first image and a second image with an off-line as a boundary, and rendering and halftone processing are sequentially performed on the first image and the second image. Specifically, when rendering of the first image is completed, halftone processing of the first image is executed in parallel with rendering processing of the second image. That is, the halftone process of the first image is promptly executed without waiting for completion of rendering of the second image. Then, the image subjected to the halftone process is output to the printing apparatus. As a result, it is possible to quickly start printing.

  In addition, the rendering execution unit has a function of calculating the upstream end and the downstream end of the image in the first direction, executes rendering in order from the image in which the downstream end is located on the downstream side in the first direction. Next, when the downstream end of the next image to be rendered becomes upstream in the first direction from the most upstream end of the upstream in the first direction among the upstream ends of the image that has been rendered, the next rendering is performed. The image processing apparatus may be configured such that it is determined that an offline exists between the scheduled image and the most upstream end. With such a configuration, it is possible to accurately detect offline.

  Alternatively, in the detection process, the rendering execution unit detects offline by scanning the target range in the second direction before the start of rendering, and renders the first image downstream in the first direction from the detected offline. The image processing apparatus may be configured to start. With such a configuration, it is possible to accurately detect offline.

  Further, the image processing apparatus may be configured to further include a storage unit that stores the first image rendered by the rendering execution unit until the halftone execution unit completes the halftone process on the first image. . As a result, the first image in which the halftone process is not completed can be stored in the storage unit. In addition, since the storage unit only needs to store the first image divided into the boundaries of offline, the capacity required for the storage unit can be suppressed.

  The printing apparatus starts printing at a timing when the image output from the image processing apparatus is accumulated up to a predetermined amount, and when printing is performed until reaching the offline state, the image output from the image processing apparatus is accumulated up to a predetermined amount. The printing system may be configured to suspend printing until it is done. With such a configuration, it is possible to efficiently print an image while dividing a plurality of images on the boundary of offline.

1 is a diagram illustrating an example of a printing system according to the present invention. FIG. 3 is a diagram schematically illustrating an example of a print execution unit of a printing apparatus. 6 is a flowchart illustrating an example of a method for creating print data by the image processing apparatus. The flowchart which shows an example of nesting. The flowchart which shows an example of rendering. The figure which shows typically the process performed by rendering. The figure which shows typically the process performed by rendering. The figure which shows typically the process performed by rendering. The figure which shows typically the process performed by rendering. The figure which shows typically the process performed by rendering. The figure which shows typically the process performed by rendering. The flowchart which shows an example of a halftone process.

FIG. 1 is a diagram showing an example of a printing system according to the present invention. The printing system 1 includes an image processing device 2 that creates print data Dp, and a printing device 3 that executes printing based on the print data Dp. The image processing apparatus 2 is a personal computer, for example, and includes a UI (User Interface) 21, a storage unit 22, and a calculation unit 23. The UI 21 includes an input device such as a mouse and a keyboard and an output device such as a display, and accepts an input operation from the user or displays information to the user. The UI 21 may be a touch panel in which an input device and an output device are integrated. The storage unit 22 is configured by an HDD (Hard Disc Drive) and stores software and various data installed in the image processing apparatus 2. The calculation unit 23 includes a CPU (Central Processing Unit) and a RAM (Random
Access Memory), for example, executes an operation defined by software.

  In the image processing apparatus 2, when a print command is input from the UI 21 by the user, the calculation unit 23 generates print data Dp corresponding to the image indicated by the print command and outputs the print data Dp to the printing apparatus 3. The calculation unit 23 constructs an arrangement determination unit 231, a RIP (Raster Image Processor) 232, and a halftone execution unit 233 by executing software. The arrangement determining unit 231 performs nesting on a plurality of images (image data) indicated by the print command. Here, nesting is arithmetic processing for determining the arrangement of a plurality of images indicated by the print command received by the UI 21 in order to suppress margins. The RIP 232 performs rendering (rasterization) on an image (image data). The halftone execution unit 233 executes halftone processing for each rendered image (raster data). As a result, print data Dp is created. The method for creating the print data Dp will be described in detail later.

  The printing apparatus 3 includes a print execution unit 31 that is a mechanical configuration that executes printing, and a controller 32 that controls the operation of the print execution unit 31. The controller 32 includes a calculation unit 321 and a storage unit 322. The calculation unit 321 includes a CPU and a RAM, and executes a calculation required for control of the print execution unit 31. The storage unit 322 includes an HDD, and stores the print data Dp received from the image processing apparatus 2.

  FIG. 2 is a diagram schematically illustrating an example of a print execution unit of the printing apparatus. The print execution unit 31 of the printing apparatus 3 includes a transport unit 311 that transports the print medium M (roll paper) in the transport direction C by roll-to-roll. The transport unit 311 includes a feeding roller 312, a pair of rollers 313 and 314, and a take-up roller 315 arranged in order in the transport direction C of the print medium M. The feeding roller 311 feeds the printing medium M wound in a roll shape in the transport direction C. The pair of rollers 313 and 314 sandwich the print medium M fed out by the take-up roller 315. The roller 314 is biased by the roller 313 and applies a certain load to the printing medium M, while the roller 313 applies a predetermined torque to the printing medium M to apply a certain tension to the printing medium M while the printing medium M is applied. Is conveyed in the conveyance direction C. Then, the take-up roller 315 takes up the print medium M from the pair of rollers 313 and 314.

  In addition, the printing apparatus 3 includes a pre-heater 316, a platen heater 317, and an after-heater 318 arranged in order in the transport direction C between the feeding roller 312 and the roller 313, and heats the printing medium M that is in contact with these upper surfaces. . Furthermore, the printing apparatus 3 includes a print head 319 that faces the platen heater 317 with a predetermined platen gap g. The print head 319 ejects ink to the print medium M supported by the platen heater 317 by an inkjet method.

  In the printing apparatus 3, the transport unit 311 intermittently transports the print medium M in the transport direction C, thereby sending an unprinted area of the print medium M onto the platen heater 317. The print head 319 performs main scanning that ejects ink while moving in the scanning direction X orthogonal to the transport direction C. At this time, the number of times (pass number) that the print head 319 executes main scanning can be set as appropriate, and the print head 319 performs main scanning for the set number of passes. Thus, when the print head 319 performs main scanning according to the control of the controller 32, the image indicated by the print data Dp is printed on the print medium M stopped by the platen heater 317.

  In the printing system 1, print data Dp is created from the image processing apparatus 2. FIG. 3 is a flowchart illustrating an example of a method for creating print data by the image processing apparatus. In the figure, a case where a print command for instructing execution of nesting printing for a plurality of images is input to the UI 21 is shown. In this case, nesting by the arrangement determining unit 231 (step S101), rendering by the RIP 232 (step S102), and halftone processing by the halftone executing unit 233 (step S103) are sequentially executed to generate the print data Dp.

  FIG. 4 is a flowchart showing an example of nesting executed in step S101 of FIG. In step S <b> 201, the arrangement determining unit 231 receives a print command input to the UI 21. Here, a print command for instructing execution of nesting printing for a plurality (N) of images I is accepted. Then, the arrangement determining unit 231 determines the arrangement of the plurality of images I (Step S202). As a result, the arrangement is determined so that a plurality of images I are two-dimensionally arranged in the transport direction C and the scanning direction X.

  FIG. 5 is a flowchart showing an example of rendering executed in step S102 of FIG. 6 to 11 are diagrams schematically showing processing executed in the rendering of FIG. 6 to 11 show an XY coordinate system including a scanning direction X and a printing direction Y. Here, the printing direction Y is a direction facing the reverse of the conveyance direction C.

  In step S301, N images I are sorted in the print start order (FIG. 6). FIG. 6 shows a state in which N (8) images I are sorted. As described above, in the printing apparatus 3, an image is printed by ejecting ink from the print head 319 onto the print medium M transported in the transport direction C. Therefore, printing is executed in order from the downstream side to the upstream side in the conveyance direction C, in other words, in the printing direction Y. Therefore, in step S301, as shown in FIG. 6, the sorting order of the N images I (the images I are assigned to the images I in the order in which the position of the downstream end Pd in the transport direction C is located on the downstream side in the transport direction C). Number in parentheses) is determined. The RIP 232 calculates the positions of the downstream end Pd and the upstream end Pu of the image I in the transport direction C as coordinates in the printing direction Y (Y coordinate). Accordingly, in step S301, the sort order of the N images I is determined in ascending order of the Y coordinate of the downstream end Pd.

  In step S302, the parameter max_y indicating the position of the upstream end Pu having the maximum Y coordinate among the upstream ends Pu of the image I that has been rendered in step S306 described later is reset to “0”. That is, the parameter max_y indicates the position of the most upstream end in the transport direction C among the upstream ends Pu of the image I that has been rendered. In step S303, the count value indicating the image I scheduled to execute steps S304 to S311 is reset to “1”. When the count value n is N or less (in the case of “YES” in step S304), steps S305 to S311 are executed for the image I (n).

  The case of n = 1 will be described with reference to FIG. In step S305, rendering is performed on the image I (1) according to the result of analyzing the contents of the image I (1). Then, the rendered image I (1) is stored in the storage unit 22 (step S306). In step S307, the Y coordinate of the upstream end Pu (1) of the image I (1) is compared with the parameter max_y. In this example, since the Y coordinate of the upstream end Pu (1) is larger than the parameter max_y (“YES” in step S308), the parameter max_y is changed from “zero” to the Y coordinate of the upstream end Pu (1) ( Step S309). In step S310, the Y coordinate of the downstream end Pd (2) of the image I (2) scheduled to be rendered next is compared with the parameter max_y. In this example, since the Y coordinate of the downstream end Pd (2) is smaller than the parameter max_y (“NO” in step S311), the count value n is incremented in step S312 and the process returns to step S304.

  Since the count value n (= 2) is N (= 8) or less, steps S305 to S311 are executed for the image I (2). This will be described with reference to FIG. In step S305, rendering is performed on the image I (2) according to the result of analyzing the contents of the image I (2). Then, the rendered image I (2) is stored in the storage unit 22 (step S306). In step S307, the Y coordinate of the upstream end Pu (2) of the image I (2) is compared with the parameter max_y. In this example, since the Y coordinate of the upstream end Pu (2) is larger than the parameter max_y (“YES” in step S308), the parameter max_y changes from the Y coordinate of the upstream end Pu (1) to the Y of the upstream end Pu (2). The coordinates are changed (step S309). In step S310, the Y coordinate of the downstream end Pd (3) of the image I (3) scheduled to be rendered next is compared with the parameter max_y. In this example, since the Y coordinate of the downstream end Pd (3) is smaller than the parameter max_y (“NO” in step S311), the count value n is incremented in step S312 and the process returns to step S304.

  Since the count value n (= 3) is N (= 8) or less, steps S305 to S311 are executed for the image I (3). This will be described with reference to FIG. In step S305, rendering is performed on the image I (3) according to the result of analyzing the contents of the image I (3). Then, the rendered image I (3) is stored in the storage unit 22 (step S306). In step S307, the Y coordinate of the upstream end Pu (3) of the image I (3) is compared with the parameter max_y. In this example, since the Y coordinate of the upstream end Pu (3) is larger than the parameter max_y (“YES” in step S308), the parameter max_y changes from the Y coordinate of the upstream end Pu (2) to the Y of the upstream end Pu (3). The coordinates are changed (step S309). In step S310, the Y coordinate of the downstream end Pd (4) of the image I (4) scheduled to be rendered next is compared with the parameter max_y. In this example, since the Y coordinate of the downstream end Pd (4) is smaller than the parameter max_y (“NO” in step S311), the count value n is incremented in step S312 and the process returns to step S304.

  Since the count value n (= 4) is N (= 8) or less, steps S305 to S311 are executed for the image I (4). This will be described with reference to FIG. In step S305, rendering is performed on the image I (4) according to the result of analyzing the contents of the image I (4). Then, the rendered image I (4) is stored in the storage unit 22 (step S306). In step S307, the Y coordinate of the upstream end Pu (4) of the image I (4) is compared with the parameter max_y. In this example, since the Y coordinate of the upstream end Pu (4) is smaller than the parameter max_y (“NO” in step S308), the parameter max_y is maintained at the Y coordinate of the upstream end Pu (3). In step S310, the Y coordinate of the downstream end Pd (5) of the image I (5) scheduled to be rendered next is compared with the parameter max_y. In this example, since the Y coordinate of the downstream end Pd (5) is smaller than the parameter max_y (“NO” in step S311), the count value n is incremented in step S312 and the process returns to step S304.

  Since the count value n (= 5) is N (= 8) or less, steps S305 to S311 are executed for the image I (5). This will be described with reference to FIG. In step S305, rendering is performed on the image I (5) according to the result of analyzing the contents of the image I (5). Then, the rendered image I (5) is stored in the storage unit 22 (step S306). In step S307, the Y coordinate of the upstream end Pu (5) of the image I (5) is compared with the parameter max_y. In this example, since the Y coordinate of the upstream end Pu (5) is smaller than the parameter max_y (“NO” in step S308), the parameter max_y is maintained at the Y coordinate of the upstream end Pu (3). In step S310, the Y coordinate of the downstream end Pd (6) of the image I (6) scheduled to be rendered next is compared with the parameter max_y.

  In this example, the Y coordinate of the downstream end Pd (6) is larger than the parameter max_y (“YES” in step S311). In this case, the RIP 232 is between the upstream end Pu (3) of the image I (3) set to the parameter max_y and the downstream end Pd (6) of the image I (6) scheduled to be rendered next. It is determined that offline L exists. Here, the offline L is a linear region parallel to the scanning direction X in which the image I does not exist continuously in the scanning direction X through the target range R including N images I.

  When the RIP 232 detects the offline L in this way, the image I arranged downstream of the offline L in the transport direction C, that is, the rendered images I (1) to I (5) accumulated in the storage unit 22 (raster data). ) Is output to the halftone execution unit 233 (step S313). Then, after the count value n is incremented in step S312, the process returns to step S304, and the same processing is repeatedly executed until the count value exceeds N.

  FIG. 12 is a flowchart showing an example of the halftone process executed in step S103 of FIG. The halftone process for the images I (1) to I (5) output to the halftone execution unit 233 is executed in parallel with the rendering (steps S304 to 312) for the subsequent images I (6) to I (8). Is done. Specifically, a layout image in which the images I (1) to I (5) are arranged according to the determination in step S202 is created (step S401), and halftone processing is executed on the layout image (step S402). ). The print data Dp created in this way is output from the halftone execution unit 233 to the printing apparatus 3 (step S403). Then, the images I (1) to I (5) are deleted from the storage unit 22 when these halftone processes are completed (step S404).

  In the printing apparatus 3, the controller 32 stores the print data Dp received from the halftone execution unit 233 in the storage unit 322. When the print data Dp stored in the storage unit 322 reaches a predetermined amount, the controller 32 causes the print execution unit 31 to start printing based on the print data Dp. Accordingly, the print execution unit 31 prints the image I on the print medium M until the offline L is reached. On the other hand, when printing up to offline L is executed, the controller 32 interrupts printing by the print execution unit 31 until a predetermined amount of print data Dp is accumulated in the storage unit 322.

  In the embodiment configured as described above, the offline L where the image I does not exist in the scanning direction X is detected (step S311). The plurality of images I are divided into groups of images I (1) to I (5) (first image) and images I (6) to I (8) (second image) with the offline L as a boundary. These are sequentially rendered and halftoned. Specifically, when the rendering of the images I (1) to I (5) is completed, in parallel with the rendering processing of the images I (6) to I (8) (in other words, asynchronously), the image I ( The halftone processes 1) to I (5) are executed. That is, the halftone process of the images I (1) to I (5) is executed promptly without waiting for the rendering of the images I (6) to I (8) to be completed. Then, the images I (1) to I (5) (print data Dp) subjected to the halftone process are output to the printing apparatus 3. As a result, it is possible to quickly start printing.

  At this time, rendering is executed in order from the image I in which the downstream end Pd is located on the downstream side in the transport direction C. In step S311 (detection process), when the downstream end Pd of the image I scheduled to be rendered next is located upstream in the transport direction C from the parameter max_y, the image I scheduled to be rendered next and the parameter max_y It is determined that an offline L exists between them. As a result, the offline L can be accurately detected.

  Further, a storage unit 22 that stores the image I rendered by the RIP 232 is provided until the halftone execution unit 233 completes the halftone process for the image I. As a result, the image I for which halftone processing has not been completed can be stored in the storage unit 22. In addition, since the storage unit 22 only needs to store the image I (in the above example, the images I (1) to I (5)) divided by the offline L as a boundary, the capacity required for the storage unit 22 is suppressed. Is possible.

  Further, when the printing apparatus 3 starts printing at a timing when the image I (print data Dp) output from the image processing apparatus 2 is accumulated up to a predetermined amount and executes printing until reaching the offline L, the image processing apparatus 2 The printing is interrupted until the image I output from is accumulated up to a predetermined amount. In this way, it is possible to efficiently print the image I while dividing the plurality of images I with the offline L as a boundary.

  As described above, in the above embodiment, the printing system 1 corresponds to an example of the “printing system” of the present invention, the image processing apparatus 2 corresponds to an example of the “image processing apparatus” of the present invention, and the printing apparatus 3 The arrangement determination unit 231 corresponds to an example of the “arrangement determination unit” of the present invention, the RIP 232 corresponds to an example of the “rendering execution unit” of the present invention, and corresponds to a halftone. The execution unit 233 corresponds to an example of the “halftone execution unit” of the present invention, the image I corresponds to an example of the “image” of the present invention, and the images I (1) to I (5) correspond to the “first” of the present invention. The image I (6) to I (8) corresponds to an example of the “second image” of the present invention, and the target range R corresponds to an example of the “target range” of the present invention. , Offline L corresponds to an example of "offline" of the present invention, and step S311 is The conveyance direction C corresponds to an example of “first direction” of the present invention, the scanning direction X corresponds to an example of “second direction” of the present invention, and the upstream end Pu corresponds to an example of “detection processing”. The “upstream end” of the invention corresponds to an example, and the downstream end Pd corresponds to an example of the “downstream end” of the present invention.

  The present invention is not limited to the above embodiment, and various modifications can be made to the above without departing from the spirit of the present invention. For example, the number of images I to be printed is not limited to the above eight.

  Moreover, in the said embodiment, the example which detected one offline L from the object range R containing the several image I was shown. However, there are naturally cases where a plurality of offline L is detected. Even in this case, by repeatedly executing steps S304 to S313, every time offline L is detected, in parallel with rendering of the image I (second image) upstream from offline L (that is, asynchronously). The rendering of the downstream image I (first image) may be executed.

  The specific method for detecting the offline L is not limited to the above-described example. For example, the RIP 232 may detect offline by scanning the target range R in the scanning direction X before the start of rendering (detection processing). This also makes it possible to accurately detect the offline L. Further, in this case, rendering to the downstream image I may be started prior to the image I (second image) upstream from the detected offline L.

  Further, the printing apparatus 3 is not limited to the above-described inkjet method, and may be a laser method, for example.

  DESCRIPTION OF SYMBOLS 1 ... Printing system, 2 ... Image processing apparatus, 231 ... Arrangement determination part, 232 ... RIP (rendering execution part), 233 ... Halftone execution part, 3 ... Printing apparatus, I ... Image, I (1) -I (5 ) ... Image (first image), I (6) to I (8) ... Image (second image), Pu ... Upstream end, Pd ... Downstream end, R ... Target range R, L ... Offline, S311 ... Detection processing , C: conveying direction (first direction), X: scanning direction (second direction)

Claims (7)

An arrangement determining unit that determines the arrangement of a plurality of images;
Of the target range including the plurality of images arranged based on the determination of the arrangement determination unit, the image does not exist through the target range in the second direction orthogonal to the first direction in which the printing medium is conveyed by the printing apparatus. A rendering execution unit that performs rendering on the plurality of images according to a result of detection processing for detecting offline;
A halftone processing unit that performs halftone processing on the image that has been rendered by the rendering execution unit, and outputs the image on which the halftone processing has been performed to the printing apparatus,
The rendering execution unit performs rendering on the first image downstream of the offline in the first direction from the offline images, and then renders the second image upstream of the offline in the first direction. And
The halftone execution unit is configured to execute a halftone process on the first image that has been rendered by the rendering execution unit in parallel with the rendering of the second image by the rendering execution unit. The rendering execution unit has a function of calculating an upstream end and a downstream end of the image in the first direction, and executes rendering in order from the image in which the downstream end is located on the downstream side in the first direction. ,
In the detection process, the downstream end of the image scheduled to be rendered next is moved in the first direction from the most upstream end of the upstream in the first direction among the upstream ends of the image that has been rendered. The image processing apparatus according to claim 1, wherein when it is upstream, it is determined that the offline exists between an image scheduled to be rendered next and the most upstream end.   In the detection process, the rendering execution unit detects the offline by scanning the target range in the second direction before the start of the rendering, and is downstream of the detected offline in the first direction. The image processing apparatus according to claim 1, wherein rendering is started on the first image.   4. The storage unit according to claim 1, further comprising: a storage unit that stores the first image rendered by the rendering execution unit until the halftone execution unit completes a halftone process on the first image. An image processing apparatus according to 1. An image processing device;
A printing apparatus that prints a plurality of images output from the image processing apparatus on the printing medium while conveying the printing medium in a first direction;
The image processing apparatus includes:
An arrangement determining unit for determining an arrangement of the plurality of images;
As a result of detection processing for detecting an off-line in which the image does not exist through the target range in a second direction orthogonal to the first direction among the target range including the plurality of images arranged based on the determination of the arrangement determination unit. And a rendering execution unit that performs rendering on the plurality of images,
A halftone processing unit that performs halftone processing on the image that has been rendered by the rendering execution unit, and outputs the image on which halftone processing has been performed to the printing apparatus;
The rendering execution unit performs rendering on the first image downstream of the offline in the first direction from the offline images, and then renders the second image upstream of the offline in the first direction. And
The halftone execution unit performs a halftone process on the first image that has been rendered by the rendering execution unit in parallel with the rendering of the second image by the rendering execution unit.   When the printing apparatus starts printing at a timing when the image output from the image processing apparatus is accumulated up to a predetermined amount and executes printing until reaching the offline, the image output from the image processing apparatus is The printing system according to claim 5, wherein printing is suspended until the predetermined amount is accumulated. Determining the placement of a plurality of images;
Detection that detects an offline state in which the image does not exist through the target range in a second direction orthogonal to the first direction in which the printing medium is conveyed by the printing apparatus among the target range including the plurality of images arranged based on the determination. Rendering the plurality of images according to a processing result; and
Performing halftoning on the rendered image;
Outputting the image on which halftone processing has been performed to the printing apparatus,
In the step of executing rendering, after rendering the first image downstream of the offline in the first direction among the plurality of images, the second image upstream of the offline in the first direction from the offline. Render,
In the step of executing halftone processing, an image processing method of executing halftone processing on the first image that has been rendered in parallel with the rendering of the second image.

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